Cardiology Teaching Package
A Beginners Guide to Normal Heart Function, Sinus Rhythm & Common Cardiac Arrhythmias
The Heart
The heart itself is made up of 4 chambers, 2 atria and 2 ventricles. De-oxygenated blood returns to the
right side of the heart via
Muscles
Breakdown: muscle fascicle fiber (cell) myofibrils sarcomeres actin & myosin
number of myofibrils determines force-generating capability of fiber
movement through cross-bridge cycling in sliding filament mechanism: myosin filaments
bind to and pu
HP AXIS
Anterior pituitary: glandular tissue
Posterior pituitary: neural tissue
releasing factors: small peptides secreted into first capillary bed, coming from hypothalamus.
delivered to AntPit, which secretes a hormone.
antPit H: tropic H; goes into cir
affect firing rate by influencing length of phase 4
PNS decreases HR by acting on vagal muscarinic receptors
SNS increases HR by acting on beta 1 adrenergic receptors, speeding up the closing of K
channels, decreasing closing speed of Na and Ca channels
B
ADH: constrict and conserve
- In response to increased osmolarity or decreased blood pressure
- Conservation of H2O
- Constrict efferent arteriole to counteract increased resistance in afferent arteriole
- Works on DCT and CD to mobilize aquaporin channel
trying to force air out quickly: forced exhalation
in normal person: intrapleural pressure can become positive. still less than alveolar pressure
(wont collapse lung). lung will contract, making pressure increase. as it moves out of system,
pressure will
SENSES
Sensory input: receptor cells can be afferent neurons that generate action potentials (smell
receptors). Can be cells that generate GPs that trigger APs in an afferent neuron
(photoreceptors, taste buds, ear hair cells)
Vision
Contracted ciliary mu
MAP = DP + (SP-DP)/3
PP = SP-DP
MAP is weighted since diastole lasts longer than systole
Flow = P/R
CO = MAP/TPR
Arterioles control perfusion of an organ:
Local control of arteriolar resistance by
- Myogenic response
o Change in wall tension to maintain p
NERVOUS SYSTEM
equilibrium potential: chemical and concentration gradients are equal and opposite.
EK = -90 mV
ENa = +60 mV
In membrane, have more K leak channels than Na. Membrane resting potential will be closer to
EK. Na/K ATPase puts 3 Na out, 2 K in.
SOMATIC NERVOUS SYSTEM
PNS somatic motor skeletal muscle
motor unit: motor neuron + muscle fibers it controls. A muscle fiber is innervated by a single
neuron.
Motor neurons have cell bodies located in grey matter of the ventral horn of the spinal cord.
r
Oxygen transport Partial Pressures of Alveolar Gases In the alveoli, the partial pressures of oxygen and
carbon dioxide vary during the respiratory cycle. As gas exchange occurs, the alveolar partial pressure of
carbon dioxide will rise and the alveolar p
ENDOCRINE SYSTEM
Hormones:
- production is most regulated aspect
- dependent on blood flow and perfusion
peptide hormones:
synthesized as preprohormones. In
RER, are cleaved to prohormone
(inactive state). In Golgi, are cleaved to
active state and package
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